Breech mechanism for breech-loading ordnance.



- Patented Aug. 27, IBM. A. T. DAWSON &. G. T. BUCKHAM.

BBEECH MECHANISM FOR BREECH LOADING DRDNANCE tion fi lad Feb. 25, 1901.

N0. 68!,53L Patented Aug. 27, I91.

A. T. DAWSON 8:. BLT. BUCKHAM. BBEEGH MECHANISM FOR BBE ECH LOADING OBDNANCE.

(Application filed Feb. 25, 1901.)

4 Sheets-Sheet 2.

(No Model.)

m imam runs on. Primaumm w-summo'ul n: c.

No. 68!,53l. Patented Aug. 27, 190i. A. T. DAWSON & G. T. BUCKHAM.

BBEEGH MEGHANISH FOB BREECH LOADING ORDNANCE.

NrTiEn TATES Price.

ARTHUR TREVOR DAWSON AND GEORGE T. BUOKHAM, OF LONDON, ENGLAND, ASSIGNORS TO VIOKERS SONS dz MAXIM, LIMITED, OF

SHEFFIELD, ENGLAND.

BREECH MECHANISM FOR BREECH-LOADING ORDNANCE.

SPECIFICATION forming part of Letters Patent No. 681,531, dated August 2'7, 1901. Application filed February 25, 901. $eria1No.48,735. (No model.)

To all whom it may concern:

Be it known that we, ARTHUR TREVOR DAWSON and GEORGE THOMAS BUGKHAM, citizens of England, residing at No. 32 Victoria Street, Westminster, in the county of London, England, have invented a certain new and useful Improvement in the Breech Mechanism of Breech-Loading Ordnance, (for which we have applied fora patent in Great Britain, dated July 24, 1900, No. 13,337,) of which the following is a specification.

Our invention relates to the construction of the breech-screw of a breech-loading gun and of the mechanism by which the breech-plug is worked and interlocked with its carrier in such a manner that when the breech is to be opened the first part of the movement of the lever which operates the carrier causes the plug to be partly turned and unlocked and the carrier to be locked, and by a further part of this movement the plug is farther turned and retracted some distance longitudinally,-and that when it is in this position the carrier is unlocked, so that it can be swung back to open the breech, but at the same time the plug is itself locked in the carrier, so that it cannot then turn in either direction. In closing the breech there are corresponding movements in reverse order-that is to say, the carrier is swung forward to the breech, where it is locked, while the plug is unlocked from the carrier. Then the plug is partly turned and moved inward longitudinally, then turned farther to become engaged with the breech-threads, and locked in the breech. We shall describe the mechanism,for this purpose referring to the accompanying drawings, in all the figures of which like reference 1etters and numerals are employed to indicate like parts.

Figures 1, 2, and 3 are transverse sections of the breech and plug, showing the plug in three positions, Fig. 1 showing it locked, Fig. 2 showing it unlocked, but not retracted, and Fig. 3 showing it in retracted position. Fig. 4: is a rear view of the breech and plug-carrier, showing the position of the parts when the breech is closed and the plug locked in the breech. Fig. 5 is a plan corresponding to Fig. 4, partly sectional. Figs. 6, 7, 8, and 9 are part sectional plans showing the plug and carrier in different positions. Fig. 10 is a section showing the inclines on the plug and carrier for efiecting retraction of the plug. Fig. 11 is a sectional detail View looking toward the inner face of the carrier, showing more clearly the sliding bolt in its intermediate position.

Referring first to Figs. 1, 2, and 3, the circumference of the breech-plug a is divided at b 12 into two equal parts, and each of these is divided into six equal parts, of which the parts 0 and d and e and f have screwthreads and the two parts 9 and h have none. The part (1 is of less radius than c by the depth of the screw-thread,and in like manner c has less radius than d and f less than c. The breech has internal threads fitting those of c (:1 cf and a space unthreaded. facing g and h. When the plug is turned, as shown in Fig. 2, one of its divisions, from the locked position, (shown in Fig. 1,) then the external threads of all the parts 0 d e fare clear of the corresponding internal threads of the breech, so that the plug is free to be retracted longitudinally. It is so retracted, as will hereinafter be described, by farther turning it to the position shown in Fig. 3, where it is free to be swung out with the carrier in the usual Way.

Although we have shown the plug with two main divisions of its circumference, each having six subsidiary divisions, obviously there might be three main divisions, each having a difierent number of subsidiary divisions, provided two of these at the extreme of each main division are like 9 andh, having no threads.

Much of the breech mechanism for looking, unlocking, and retracting the breechplug is of known kind operating in the known manner-that is to say, the handle 1, which is pivoted on the pin 2, on which the carrier 3 is hinged, has fixed on it a skew-toothed pinion 4, which gears with a skew-toothed pinion 5, mounted in a recess of the carrier; On the axis of the pinion 5 is fixed a short toggle-link 6, the longer link 7 of which works on a pin 8, projecting from the rear face of the plug. On swinging the handle 1 over to the right the pinion 5 is turned, moving the toggle-links, and so turning the plug so as to unlock .and retract it, and then by the further movement of the lever 1 the carrier and plug are swung away from the breech. This mechanism, which, so far as We have now described it, is old and known, is, according to our present invention, modi-. fied, so as to effect partial retraction of the plug after it has been turned to the position shown in Fig. 2 and to effect locking and unlocking of the carrier.

For the purposeof effecting retraction of the plug as it is completing the rotation caused by the movement of the handle 1 we provide, as shown in Fig. 10, on the rear of the plug an inclined offset or male screw-thread 9, which is engaged in a corresponding inclined recess or female thread 10, formed in the carrier. Besides these threads at the left side of the plug and carrier there is also at the right side a short ofiset or male thread 11 on the plug to engage in a recess or female thread 12 in the carrier. These engaged threads 9 and 10 and 11 and 12 serve to hold the plug to the carrier as the carrier is swung on its hinge. The rear of the plug a has formed integral therewith a rear projection cut away, so as to form the forward part in a cam 9, the rear part to a projection or cam 13, an inclined lug 19', and arecess 22. The cam 13 engages with a forward projection 14 from a sliding bolt 15, which is retracted by a spring 16, but is forced by the downward movement of the cam 13 to engage in a hole 17,. formed in a bracket 18, which is fixed to the breech of the gun, the carrier being thus bolted close to the breech during the unlocking and retraction of the plug. When the retraction of the plug is being completed, the

' inclined lug 19 on the projection at the rear of the plug and which is arranged outward and to the left of the cam 13 comes to bear on the left side of the projection 14, and thus causes withdrawal of the bolt 15, leaving the carrier free to be swung away from the breech. When this swinging begins, an inclined projection 20 from the under side of the bolt 15 is withdrawn from an inclined recess 21, formed in a projection from the bracket 18, and the spring 16 in retracting the bolt 15 causes the projection 14 to engage in the recess 22 above the cam 13, and thus prevents the breech-plug from turning while the carrier is away from the breech. Figs. 6, 7, and 8 of the drawings show the relative positions of the locking-bolt and cams when the plug is turned until the radial lines 6, 7, and 8 on Fig. 4 are in the horizontal position. In closing the breech the projection 20 enters the recess 21 and causes the bolt 15 to move to the left, withdrawing the projection 14 from the recess 22, and so leaving the plug free to be turned. As the plug when it begins to turn is by the operation of the threads 9 and 10 and 11 and 12 advanced into the breech the upper part of the cam 13, acting on the projection 14, causes the bolt 15 to engage in the hole 17, so looking the carrier to the breech while the plug is being turned.

Having thus described the nature of this invention and the best means we know for carrying the same into practical efiect, we claim 1. In a breech-loading gun, the combination with the breech thereof provided with stepped threads, of a plug having its circum ference symmetrically divided into two equal portions, each of said portions divided into a series of sections, two of the said sections having smooth surfaces and the remaining sections provided with stepped threads corresponding with the threads of the breech, means for rotating the plug within the breech to disengage the threads of the latter from the threads of the former, and means oper-' ating during the rotation of the breech-plug after the latter has been released from the breech and adapted to cause the retracting of the plug from the breech.

2. In a breech-loading gun, the combina tion with the breech thereof provided with stepped threads, of a breech-plug mounted therein and having its periphery formed with stepped threads engaging the threads of the breech for locking the plug therein, a carrier engaging said plug for swinging the same to and from the breech, means for rotating the plug within the breech to release the threads of the plug from the threads of the breech, means permitting an extra rotation of the plug after the threads thereof have been released from the threads of the breech, means for causing a cam engagement between the carrier and the plug for retracting the latter from the breech during an extra rotation given to the plug after the threads of the plug and breech are released from their engagement with one another, and means for swinging the carrier and plug to and from the breech.

3. In combination, a breech, a breech-plug having a recess in the rear face thereof, a carrier having recesses on its inner face, inclined offsets carried by said plug and adapted to engage in the recesses of the carrier for connecting the plug thereto, a spring -retraoted bolt arranged in the carrier, projections on the forward and lower faces of said bolt, a bracket attached to the breech and provided with an opening and an inclined recess, a cam 13 on the said plug, said cam adapted to engage the projection on the forward face of the bolt for forcing the latter Ids and the projection on the lower face thereof our hands in presence of two subscribing witinto the opening and. recess, respectively, of nesses. the bracket, and a lug adapted to engage the projection on the forward face of the bolt for E 5 releasing the letter from the bracket and forcing said projection into the recess in the WVitnesses: plug. p O. A SEARLE,

In testimony whereof We have hereunto set HENRY KING. 

